Malicious PDF — malware analysis report

Static analysis result for SHA-256 91e8978ee7108294…

MALICIOUS

PDF

83.2 KB Created: 2021-09-15 17:13:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d68ef94d43e906fff88ea43bee57c1e8 SHA-1: 8c7ab0a484eb84dcfd28b16273dc306c6a0877e8 SHA-256: 91e8978ee710829444a168cd2ad6994ae06b43e3a30ef3caca068653385a3b88
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or SEO spam. The presence of multiple external URIs and link farm heuristics supports the classification as a malicious link distribution mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8637

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://i-physiology.ru/upload/xifopexowakoso.pdf
    • https://karolinanowak.com/userfiles/file/lareniwedozaxilineri.pdf
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138f2b0ed2c3---rukegidemiradunojaluke.pdf
    • https://rusepress.com/uploads/wysiwyg/files/duvigosikizudunu.pdf
    • https://0955205219.jwa.tw/userfiles/files/99387091041.pdf
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/74d86a23eca1bba74581eb26e0466ee5/77817288451.pdf
    • https://kluchar.net/klucharnet/images/file/vuzezabo.pdf
    • http://pegastelco.com/pictures/files/dusesedasulejuzit.pdf
    • http://www.ambatownship.com/ckfinder/userfiles/files/sigapuvuxo.pdf
    • https://playerpress.com/ckfinder/userfiles/files/75627303821.pdf
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/38uhon605dj26cepb5hhc1mk95/zapubipe.pdf
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f221701ab6---finumozino.pdf
    • https://vanrun-it.nl/userfiles/files/develodujapazugetafop.pdf
    • http://planetamama.ru/files/file/37023287165.pdf
    • https://gianlucabruno.it/dati/upload/file/vuxirolila.pdf
    • http://tokyosushilohaus.com/uploads/files/32669396584.pdf
    • https://jasmijnbloemengroen.nl/userfiles/file/331943539.pdf
    • http://jindi2010.com/uploadfile/files/58105821245.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b417b41017---furofukegi.pdf
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a737e60397---11510381048.pdf
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613d82bf4c00d---pusifi.pdf
    • https://aventura-agence.lu/userfiles/files/31241401172.pdf
    • https://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/54619864066.pdf
    • https://eldorado777.ro/upload/editor/file/sidijadari.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=the+walking+dead+season+1+torrent+magnet
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec8c.bin
9d72af1856c164426a61294e6320cc7092ea294d4521b518c72179ffff092288
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC8C 10888 bytes
font_01_sfnt_off0001056e.bin
e4c5ad43d811aad62318a04ebe72670cf3e98edfca5016efaf0407f426bd41d9
pdf-font-stream PDF embedded font (sfnt) at offset 0x1056E 18332 bytes
font_02_sfnt_off00013503.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13503 16792 bytes